1. Field of the Invention
The present invention relates to a lane boundary marking line detection device and an electronic control device.
2. Description of Related Art
Recently, to increase the safety of vehicle travel and to support a driver in the driving operation, a device is available that captures the vehicle's surroundings with an imaging unit mounted on the vehicle and, based on the captured image information, recognizes the white lines in front of the vehicle for controlling the vehicle's travel. For example, the on-vehicle white line recognition device described in Japanese Patent Application Publication No. 2012-22574 (JP 2012-22574 A) detects the white lines, one on the right and the other on the left, based on the image in which the vehicle's lane is captured. If the reliability of one of the right white line and left white line is low, this on-vehicle white line recognition device offsets the high-reliability white line to the low-reliability white line side to correct the low-reliability white line. In this way, this on-vehicle white line recognition device can accurately recognize the white lines of the vehicle's lane even if a noise is detected when the vehicle approaches a branching road.
However, when one of the right white line and left white line cannot be recognized due to a scrape in the white line and, as a result, the other white line, which is recognized, is offset to the side on which the white line cannot be recognized, there is a possibility of incorrect correction. For example, if the detection reliability of one of the white lines is low in an area near a road branching point, the high-detection-reliability white line is offset to the side of the low-detection-reliability white line to correct the low-detection-reliability white line. In this case, however, if the high-detection-reliability white line is a white line that does not form a horizontal pair with the low-detection-reliability white line in the lane, this correction results in incorrect correction. That is, if the low-detection-reliability white line is corrected by offsetting the high-detection-reliability white line that does not form a horizontal pair in the lane, the shape of the corrected white line differs from the actual shape of the low-detection-reliability white line. Thus, when the low-detection-reliability white line is corrected by offsetting the high-detection-reliability white line, there is a possibility that the estimated shape of the low-detection-reliability white line is different from the actual shape of the white line.